Subsidence of the Sino-Myanmar oil and gas pipelines leads to pipeline bending, deformation, and even rupture. Therefore, pipeline settlement monitoring is of great significance for pipeline construction and maintenance. The persistent scatterer interferometric synthetic aperture radar (PS-InSAR) technology has the advantages of all-day use, all-weather use, wide monitoring range, and high precision. Taking the 3-km buffer zone on both sides of the Ruokai mountain section of the Sino-Myanmar natural gas pipeline as the study area, the abnormal deformation area is obtained by the PS-InSAR method. Further, combined with multisource data such as slope, slope direction, vegetation, and soil types in the study area, a risk assessment model is established to evaluate the landslide risk for the Sino-Myanmar oil and gas pipelines and determine the risk level of pipeline subsidence. The main conclusions are as follows: The PS-InSAR method based on the fusion of ascending and descending orbits is used for deformation monitoring, and a total of 90 areas with large deformation are obtained. The average variation is between -25 mm and +25 mm, and most areas are stable. Based on slope, aspect, and other multisource data, the landslide risk level and pipeline operation safety level are determined. The results show that there are 13 first-level landslide risk areas, 18 second-level landslide risk areas, and 59 third-level landslide risk areas, and there are 10 first-level pipeline risk areas, 14 second-level pipeline risk areas, and 66 third-level pipeline risk areas.